Residents in some parts of the Midlands say they haven't received post for eleven days.
Royal Mail says it's been dealing with a backlog for the past two weeks, caused by severe weather conditions and resourcing challenges relating to sickness, absence and recruitment.
They said that the vast majority of customers across the region are "receiving deliveries at least every other day, if not daily".
Areas in the Midlands facing disruption to postal services include:
Brierley Hill
Coleshill
Dudley
Eastwood
Kidderminster
Kingswinford
Kitts Green
Lichfield
Northfield
Oakengates
Quinton
Redfern Park
Rednal
Smethwick
Sutton Coldfield
Tipton
Wednesbury
NHS trusts and banks use the Royal Mail's "economy" service, rather than first class or second class services.
Royal Mail said: "Items sent using this service are only delivered alongside a First or Second Class item or after five working days from posting."
"As a result, some customers may see a number of items arrive at the same time, in line with the specification of that service."
The Royal Mail website states: “Severe weather conditions and resourcing challenges have had an impact on deliveries in the last two weeks.
"We apologise for any inconvenience caused, and our posties are going above and beyond to ensure deliveries return to normal as quickly as possible.”
With warnings of Storm Chandra, they are warning of further possible disruption to postal deliveries.